LEGISLATION : Kennedy Health Plan Not Coming From Left Field : Longtime liberal champion of reform signals a willingness to negotiate. So far, most Republicans appear unswayed.

By the time Sen. Edward M. Kennedy (D-Mass.) stepped into the den of his Virginia home, it was after 9 p.m. on a day full of events momentous and ordinary.

He had watched as his protege Stephen G. Breyer was presented as President Clinton’s Supreme Court nominee, dashed to the South Lawn for a ceremony marking the passage of an education bill he had steered through the Senate, met with labor leaders on striker replacement legislation and rooted in vain for his stepson’s Little League team.

But the day’s work was far from over. Downstairs, his highly regarded Labor and Human Resources Committee staff was working feverishly on the biggest project of all--sweeping health care legislation, which the committee will begin to debate and vote upon today.

Kennedy has championed the cause of health reform since 1970, long before it was politically fashionable. The responsibility now falls on him to revive Clinton’s stalled effort to produce major legislation this year. Four other panels on Capitol Hill share jurisdiction over the issue, and to one degree or another all their deliberations have bogged down.

Thus, Kennedy was well-positioned to take command of the process last week when he produced his own version of Clinton’s proposal--one that he said addressed three of the four areas most criticized by the bill’s opponents. His bill eliminated mandatory purchasing cooperatives, instead making them one of several options available to most people; eased up a bit on the smallest businesses, and found some extra deficit reduction.

On the final area of contention--Clinton’s proposal to rein in health costs with government-imposed premium caps--Kennedy said he is willing to entertain other ideas.

Although the changes are minimal in some respects, they surprised many on Capitol Hill, given that Kennedy has enough liberal votes on his committee to pass virtually any bill he chooses. What they seem to represent is a signal to Republicans and moderate Democrats that the old warhorse of the left is willing to negotiate, if the compromise holds any chance of winning their votes.

Kennedy has been quietly working for months, meeting in small groups and with individual Democrats and Republicans, carefully taking note of their pet causes and their personal beefs.

For Sen. William V. Roth Jr. (R-Del.), he included an option under which anyone could enroll in the health plan now enjoyed by lawmakers and other federal employees; for Sen. Orrin G. Hatch (R-Utah), there was more money for community health centers; for Sen. Mark O. Hatfield (R-Ore.), funds for research. And to broaden its appeal, there are richer benefits for women, children and the disabled.

Thus far, Republicans say they are not ready to take the bait. “I thought it would have come closer to the bipartisan middle. It’s got an awful lot of regulation in it,” says Sen. Dave Durenberger (R-Minn.), who is considered a bellwether of moderate GOP sentiment.

Conservatives are even more blunt. “The Kennedy plan is an accountant’s nightmare and a bureaucrat’s dream,” Sen. Dan Coats (R-Ind.) said.

But Kennedy said he was not concerned by the rhetoric. “There’s always a tightening up of emotion and feeling as you come closer to the time of decision-making,” he said. “But eventually, the process moves forward.”

It appears now that only one of his committee’s Republicans--James M. Jeffords of Vermont--backs his bill. But he hopes Durenberger, Hatch and Nancy Landon Kassebaum of Kansas will support at least part of the plan.

If so, it could give some guidance to the deliberations of the Finance Committee, which has a far stronger GOP minority. Hatch and Durenberger are also members of that panel.

A strong bill, Kennedy said, could also have “a profound impact in the House,” where many members are afraid to take too controversial a stand for fear of being undercut--as they have been in the past--by the Senate.

But he cautioned against reading too much into what happens in any committee. “This has been a long process . . . toward the ultimate resolution, which I think will be on the Senate floor some time in the late spring or early summer,” he said. “That will be the defining time.”